104 KAl'lU I'Ul'ULAllUiN UKUWTH —II yield dramatic advances in his adult mental and physical capacities.* For the rest of his life, the growing productive potential of his time must be allocated between current earnings which may be saved or immediately consumed and earnings foregone which can be invested in his future productive capacity, or human capital (22).~t" To delay a child's entry into the full-time labor force so that he may acquire general education or specific vocational skills, parents must reallocate family resources. They may decide to rear fewer children, reduce family per capita consumption, reduce other forms of household savings and investment, or some combination of these three to increase their investments in their existing children. Widespread evidence of declining labor force participation rates and increasing school enrollment rates among children in both low and high income countries implies that the costs of rearing and schooling children are rising.i Some of this increase in child costs is directly borne by parents, apparently on a voluntary basis. What has motivated parents to sustain these increasing costs per child at a time when the recent decline in child death rates has led to an increase in the number of children parents must support? (25, 26). Will these concurrent demands on family resources be responsible for new patterns of parent economic and reproductive behavior? How PARENT DEMAND FOR CHILDREN CHANGES In the course of the postwar development process, certain changes in the family environment have hastened the rate of family formation, increased the costs associated with this process, and may have raised the returns from human capital in comparison with those from unskilled labor and physical capital. Several of these changes are examined in this section from the viewpoint of the family, to discern what effects they are likely to have on parent reproductive and economic behavior. Decline in Death Rates The immediate cause of the "population explosion" was the abrupt decline in death rates in much of the less developed world shortly after World War II.§ In general, the reduction in death rates was proportionately greater *See, for example, (23, 24) and Wray, J. D., "Population Pressure on Families: "Family Size and Child Spacing," in this volume. 1"A formal model of this life cycle process is presented in (12). •i-See Gavin W. Jones, "Effect of Population Change on the Attainment of Educational Goals in the Developing Countries," in this volume. §This sharp reduction in death rates is often attributed to the easily transferred techniques of public sanitation and health, including new disease-control measures, such as spraying pesticides. However, there were improvements in consumption levels in the-20).ore recently, subsidized stuc legal mechanisms to redress this institutional shortcoming of the famil; of view of society's long-run welfare.ive the relationship, then one might argue the nonpecuniary returns to additional children had become strongly negative.